I have an 7yr old Click 125, with a kickstarter, a main reason I bought it. I regularly leave it for 3 to 4 months, under cover. When I return I always start it with the KS, only needs 2 kicks or so, and I only use the KS for a few days when the engine is cold.
It still has the original battery and the bike has only 6k on it, very low use and mostly around town.
Previous bike was a 125cc Suzuki underbone, with a KS and got 8yrs from that battery as well.